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Title: Multispacecraft observations of the electron current sheet, neighboring magnetic islands, and electron acceleration during magnetotail reconnection

Abstract

Open questions concerning structures and dynamics of diffusion regions and electron acceleration in collisionless magnetic reconnection are addressed based on data from the four-spacecraft mission Cluster and particle-in-cell simulations. Using time series of electron distribution functions measured by the four spacecraft, distinct electron regions around a reconnection layer are mapped out to set the framework for studying diffusion regions. A spatially extended electron current sheet (ecs), a series of magnetic islands, and bursts of energetic electrons within islands are identified during magnetotail reconnection with no appreciable guide field. The ecs is collocated with a layer of electron-scale electric fields normal to the ecs and pointing toward the ecs center plane. Both the observed electron and ion densities vary by more than a factor of 2 within one ion skin depth north and south of the ecs, and from the ecs into magnetic islands. Within each of the identified islands, there is a burst of suprathermal electrons whose fluxes peak at density compression sites [L.-J. Chen et al., Nat. Phys. 4, 19 (2008)] and whose energy spectra exhibit power laws with indices ranging from 6 to 7.3. These results indicate that the in-plane electric field normal to the ecs can bemore » of the electron scale at certain phases of reconnection, electrons and ions are highly compressible within the ion diffusion region, and for reconnection involving magnetic islands, primary electron acceleration occurs within the islands.« less

Authors:
; ;  [1]; ; ; ;  [1];  [2];  [3];  [4];  [5];  [6]
  1. Space Science Center, University of New Hampshire, Durham, New Hampshire 03824 (United States)
  2. ESTEC/ESA, Keplerlaan 1, 2201AZ Noordwijk (Netherlands)
  3. Institute of Atmospheric Physics, Prague CZ14131 (Czech Republic)
  4. Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking RH5 6NT (United Kingdom)
  5. Swedish Institute of Space Physics, SE-75121 Uppsala (Sweden)
  6. Max-Planck-Institute for Solar System Research, D-37191 Katlenburg-Lindau (Germany)
Publication Date:
OSTI Identifier:
21277184
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 16; Journal Issue: 5; Other Information: DOI: 10.1063/1.3112744; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ACCELERATION; CURRENTS; DISTRIBUTION FUNCTIONS; ELECTRON DENSITY; ION DENSITY; MAGNETIC ISLANDS; MAGNETIC RECONNECTION; MAGNETOTAIL; PLASMA DIAGNOSTICS; PLASMA SIMULATION; TAIL ELECTRONS

Citation Formats

Lijen, Chen, Bessho, Naoki, Bhattacharjee, Amitava, Center for Integrated Computation and Analysis of Reconnection and Turbulence, University of New Hampshire, Durham, New Hampshire 03824, Lefebvre, Bertrand, Vaith, Hans, Puhl-Quinn, Pamela, Torbert, Roy, Asnes, Arne, Santolik, Ondrej, Faculty of Mathematics and Physics, Charles University, Prague CZ18000, Fazakerley, Andrew, Khotyaintsev, Yuri, and Daly, Patrick. Multispacecraft observations of the electron current sheet, neighboring magnetic islands, and electron acceleration during magnetotail reconnection. United States: N. p., 2009. Web. doi:10.1063/1.3112744.
Lijen, Chen, Bessho, Naoki, Bhattacharjee, Amitava, Center for Integrated Computation and Analysis of Reconnection and Turbulence, University of New Hampshire, Durham, New Hampshire 03824, Lefebvre, Bertrand, Vaith, Hans, Puhl-Quinn, Pamela, Torbert, Roy, Asnes, Arne, Santolik, Ondrej, Faculty of Mathematics and Physics, Charles University, Prague CZ18000, Fazakerley, Andrew, Khotyaintsev, Yuri, & Daly, Patrick. Multispacecraft observations of the electron current sheet, neighboring magnetic islands, and electron acceleration during magnetotail reconnection. United States. https://doi.org/10.1063/1.3112744
Lijen, Chen, Bessho, Naoki, Bhattacharjee, Amitava, Center for Integrated Computation and Analysis of Reconnection and Turbulence, University of New Hampshire, Durham, New Hampshire 03824, Lefebvre, Bertrand, Vaith, Hans, Puhl-Quinn, Pamela, Torbert, Roy, Asnes, Arne, Santolik, Ondrej, Faculty of Mathematics and Physics, Charles University, Prague CZ18000, Fazakerley, Andrew, Khotyaintsev, Yuri, and Daly, Patrick. 2009. "Multispacecraft observations of the electron current sheet, neighboring magnetic islands, and electron acceleration during magnetotail reconnection". United States. https://doi.org/10.1063/1.3112744.
@article{osti_21277184,
title = {Multispacecraft observations of the electron current sheet, neighboring magnetic islands, and electron acceleration during magnetotail reconnection},
author = {Lijen, Chen and Bessho, Naoki and Bhattacharjee, Amitava and Center for Integrated Computation and Analysis of Reconnection and Turbulence, University of New Hampshire, Durham, New Hampshire 03824 and Lefebvre, Bertrand and Vaith, Hans and Puhl-Quinn, Pamela and Torbert, Roy and Asnes, Arne and Santolik, Ondrej and Faculty of Mathematics and Physics, Charles University, Prague CZ18000 and Fazakerley, Andrew and Khotyaintsev, Yuri and Daly, Patrick},
abstractNote = {Open questions concerning structures and dynamics of diffusion regions and electron acceleration in collisionless magnetic reconnection are addressed based on data from the four-spacecraft mission Cluster and particle-in-cell simulations. Using time series of electron distribution functions measured by the four spacecraft, distinct electron regions around a reconnection layer are mapped out to set the framework for studying diffusion regions. A spatially extended electron current sheet (ecs), a series of magnetic islands, and bursts of energetic electrons within islands are identified during magnetotail reconnection with no appreciable guide field. The ecs is collocated with a layer of electron-scale electric fields normal to the ecs and pointing toward the ecs center plane. Both the observed electron and ion densities vary by more than a factor of 2 within one ion skin depth north and south of the ecs, and from the ecs into magnetic islands. Within each of the identified islands, there is a burst of suprathermal electrons whose fluxes peak at density compression sites [L.-J. Chen et al., Nat. Phys. 4, 19 (2008)] and whose energy spectra exhibit power laws with indices ranging from 6 to 7.3. These results indicate that the in-plane electric field normal to the ecs can be of the electron scale at certain phases of reconnection, electrons and ions are highly compressible within the ion diffusion region, and for reconnection involving magnetic islands, primary electron acceleration occurs within the islands.},
doi = {10.1063/1.3112744},
url = {https://www.osti.gov/biblio/21277184}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 5,
volume = 16,
place = {United States},
year = {Fri May 15 00:00:00 EDT 2009},
month = {Fri May 15 00:00:00 EDT 2009}
}